Simplify the following expression: $y = \dfrac{z}{7z + 11} - \dfrac{-z + 11}{7z + 11}$
Explanation: Since the expressions have the same denominator we simply subtract the numerators: $y = \dfrac{z - (-z + 11)}{7z + 11}$ Distribute the negative sign: $y = \dfrac{z + z - 11}{7z + 11}$ Combine like terms: $y = \dfrac{2z - 11}{7z + 11}$